I agree that the FB thing was designed for you. She knew you'd either see it or hear about it. Look at it this way, if you met someone that touched your heart, would you advertise it to everyone in her known world? There's a huge difference between saying your happy and really being happy.
I don't know if my wife has had or is having a PA. I'm pretty certain about the EA and it took me over a year to get past it. That's not to say I don't have my bad days where the hurt resurfaces some, but I just don't see my wife (until she files) happy at all. She can party with friends and laugh and live, but as the world begins to slow down and take shape, love lost is love lost. I see a clear pattern in her friendships and how misery attracts misery, but as her friends find happiness, the phone calls stop coming for her.
Where are you in all this? You don't live with your wife so maybe it can be helpful if you take more control of your surroundings. Paint a room, put up a shelf. Find something that will distract you and give you a sense of achievement. I'm no expert and we're all different. I went back to school. I've made myself busy so that I'd have something to occupy my mind during downtime. I reserve the hardest courses for the summer when my wife stays out later more often. I don't think about her as much when I have to focus on school work and studying. I'm trying to take advantage of my wife's experience by learning how to not be so lazy and selfish and more dedicated to getting things done.